This invention relates to manually-operated digital controls, and more particularly to a digital joystick control interface system.
This invention further relates to copending patent application Ser. No. 785,006 by Kastner et al., entitled System for Displaying Character and Graphic Information on a Color Video Display; Ser. No. 785,144 by Burson et al., entitled Digital Joystick Control; and Ser. No. 785,143 by Burson, entitled System to Control Velocity Vector of a Display Cursor, each filed of even date with and assigned to the assignee of the present invention. This invention also relates to Ser. No. 791,913, filed Apr. 28, 1977, by Trenkler et al., entitled Video Game With Portable Control Units.
In order to interface a digital joystick having, for example, four bits of resolution per axis, would normally require eight lines for data output plus one common input line. If the digital joystick were to be incorporated in a remote unit, a 9-conductor cable would be required to connect the remote unit to the main console containing, for example, video game circuitry. If, in addition to the digital joystick, a 20-key matrix keyboard were to be included in the remote unit, the number of conductors required in the cable would be increased to 18 (the 9 lines for the joystick plus 5 input scan lines and 4 output lines from the keyboard). Also, in order to interface the twelve data output lines to a 4-bit data bus, would require a multiplexer.
It is therefore an object of the present invention to provide a digital control interface to a system which reduces the number of conductors required to couple the digital control to the controlled circuitry of the system.
It is another object of the invention to provide an improved interface between a remote digital control unit and the controlled circuitry located in some other unit of the system.
It is a further object of the invention to provide an improved interface between a remote control unit having a manually-operated digital joystick and key matrix keyboard and the controlled circuitry located in some other unit of the system.
It is yet another object of the invention to provide an improved video game having a digital joystick.
Still another object of the invention is to provide an improved interface between a manually-controlled digital joystick and a video game.
A still further object of the invention is to provide a video game system with an improved interface between a pair of remote units each including a digital joystick and key matrix keyboard and the main circuitry of the video game located in a central unit with a reduced number of conductors in the cables therebetween.
Yet another object of the invention is to provide a system with a remote control unit having a digital joystick and key matrix keyboard which unit is coupled to a data bus without the requirement of a multiplexer.